NationMaster - Encyclopedia: Pioneer 11

Pioneer 11 was the second mission to investigate Jupiter and the outer solar system and the first to explore the planet Saturn and its main rings. Pioneer 11 (also called Pioneer G), unlike Pioneer 10 which only visited Jupiter, used Jupiter's mass in a gravitational slingshot to alter its trajectory toward Saturn. It passed close to Saturn and then it followed an escape trajectory from the solar system. File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... // Technical usage in physical sciences Established official technical definition : In the physical sciences, the weight of an object has a particular technical meaning. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... April 6 is the 96th day of the year in the Gregorian calendar (97th in leap years). ... 1973 (MCMLXXIII) was a common year starting on Monday. ... It has been suggested that leap second be merged into this article or section. ... Image File history File links Traj_pjm. ... Image File history File links Traj_pjm. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... The outer solar system (as opposed to the outer planets) is that part of the Solar System which begins at roughly the orbit of Neptune and terminates at maximum orbit distance, approximately one Light Year from the sun in terms of orbital measurements. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... Pioneer 10 in the final stage of construction Pioneer 10 was the first spacecraft to travel through the asteroid belt, and was the first spacecraft to make direct observations of Jupiter. ... Mass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... It has been suggested that sling effect be merged into this article or section. ... A trajectory is an imagined trace of positions followed by an object moving through space. ... Major features of the solar system (not to scale): The Sun, the eight planets, the asteroid belt, the dwarf planet Pluto, and a comet. ...

The spacecraft was launched from Cape Canaveral on April 6, 1973. It is 2.9 meters long and has a 2.74-meter-diameter high-gain antenna, topped with a medium-gain antenna. A low-gain, omnidirectional antenna is mounted below the high-gain dish. The spacecraft contains two radioisotope thermoelectric generators (RTGs), which generated 144 W at Jupiter, but had decreased to 100 W by the time it reached Saturn. There were three reference sensors: a star (Canopus) sensor, and two Sun sensors. Attitude position could be calculated from the reference direction to Earth and Sun, with the known direction to Canopus as backup. Pioneer 11's star sensor gain and threshold settings were modified, based on experience gained from the settings used on Pioneer 10. Three pairs of rocket thrusters provided spin-axis control (maintained at 4.8 rpm) and change the spacecraft's velocity. The thrusters could be either fired steadily or pulsed, by command. A spacecraft is designed to leave Earths atmosphere and operate beyond the surface of the Earth in outer space. ... Cape Canaveral from space, August 1991 Cape Canaveral (Cabo CaÃ±averal in Spanish) is a strip of land in Brevard County, Florida, United States, near the center of that states Atlantic coast. ... April 6 is the 96th day of the year in the Gregorian calendar (97th in leap years). ... 1973 (MCMLXXIII) was a common year starting on Monday. ... A yagi antenna Most simply, an antenna is an electronic component designed to send or receive radio waves. ... A radioisotope thermoelectric generator (RTG) is a simple electrical generator which obtains its power from radioactive decay. ... The watt (symbol: W) is the SI derived unit of power. ... Canopus (Î± Car / Î± Carinae / Alpha Carinae) is the brightest star in the southern constellation of Carina, and the second brightest star in the sky, with a visual magnitude of âˆ’0. ... The Sun is the star at the center of our solar system. ... Earth (often referred to as the Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth largest. ... A thruster is a small propulsive device used by spacecraft and watercraft for station keeping, attitude control, or long duration low thrust acceleration. ... The velocity of an object is simply its speed in a particular direction. ...

Instruments studied the interplanetary and planetary magnetic fields; solar wind properties; cosmic rays; the transition region of the heliosphere; neutral hydrogen abundance; distribution, size, mass, flux, and velocity of dust particles; Jovian aurorae; Jovian radio waves; the atmospheres of planets and satellites; and the surfaces of Jupiter, Saturn, and some of their satellites. The instruments carried for these experiments were a magnetometer, a plasma analyzer (for solar wind), a charged-particle detector, an ion detector, non-imaging telescopes with overlapping fields of view to detect sunlight reflected from passing meteoroids, sealed pressurized cells of argon and nitrogen gas for measuring penetration of meteoroids, an ultraviolet photometer, an infrared radiometer, and an imaging photopolarimeter, which produced photographs and measured their polarization. Further scientific information was obtained from celestial mechanics and occultation phenomena. Image File history File links Download high-resolution version (3000x2254, 774 KB) Diagram shows Pioneer 10s systems From http://www. ... Image File history File links Download high-resolution version (3000x2254, 774 KB) Diagram shows Pioneer 10s systems From http://www. ... Current flowing through a wire produces a magnetic field (B, labeled M here) around the wire. ... The plasma in the solar wind meeting the heliopause For the British comic, see Solar Wind (comic). ... Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ... The heliosphere is a bubble in space produced by the solar wind. ... The hydrogen line refers to the spectral line created by changes in the energy state of neutral hydrogen and occurs at 1420. ... In the various subfields of physics, there exist two common usages of the term flux, both with rigorous mathematical frameworks. ... After just three years of use dust has blocked this laptop heat sink, making the computer unusable Dust is a general name for minute solid particles with diameter less than 500 micrometers (otherwise see sand or granulates) and, more generally, for finely divided matter. ... Radio frequency, or RF, refers to that portion of the electromagnetic spectrum in which electromagnetic waves can be generated by alternating current fed to an antenna. ... Atmosphere is the general name for a layer of gases that may surround a material body of sufficient mass. ... A satellite is any object that orbits another object (which is known as its primary). ... A magnetometer is a scientific instrument used to measure the strength of magnetic fields. ... The plasma in the solar wind meeting the heliopause For the British comic, see Solar Wind (comic). ... The Compact Muon Solenoid (CMS) is an exampel of a large particle detector. ... 50 cm refracting telescope at Nice Observatory. ... Prism splitting light Sunlight in the broad sense is the total spectrum of electromagnetic radiation given off by the Sun. ... Look up meteoroid in Wiktionary, the free dictionary. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... A photograph (often shortened to photo) is an image created by focusing light onto material having a light-sensitive coating. ... In electrodynamics, polarization (also spelled polarisation) is a property of waves, such as light and other electromagnetic radiation. ... Celestial mechanics is a division of astronomy dealing with the motions and gravitational effects of celestial objects. ...

Jupiter Encounter

During its closest approach, December 4, 1974, Pioneer 11 passed to within 34,000 km of Jupiter's cloud tops and obtained dramatic images of the Great Red Spot, made the first observation of the immense polar regions, and determined the mass of Jupiter's moon, Callisto. Using Jupiter's mass in a gravitational slingshot, the probe altered its trajectory towards Saturn. December 4 is the 338th day (339th on leap years) of the Gregorian calendar. ... 1974 (MCMLXXIV) was a common year starting on Tuesday. ... km redirects here. ... The Great Red Spot as seen from Voyager 1 in 1979. ...

Saturn Encounter

It passed by Saturn on September 1, 1979, at a distance of 21,000 km from Saturn's cloud tops. September 1 is the 244th day of the year (245th in leap years). ... This page refers to the year 1979. ...

(By this time Voyager 1 and Voyager 2 had already passed Jupiter and were also en route to Saturn.) It was decided to target Pioneer 11 to pass through the Saturn ring plane at the same position that the soon-to-come Voyager probe would use in order to test the route before Voyager arrived. If there were faint ring particles that could damage a probe in that area, mission planners felt it was better to learn about it via Pioneer. Thus, Pioneer 11 was acting as a "pioneer" in a true sense of the word. (If danger was detected, then the Voyager probes could be rerouted further away from the rings, but missing the opportunity to visit Uranus and Neptune in the process.) Voyager 1 lifted off with a Titan 3E Centaur The Voyager 1 spacecraft is an 815-kilogram unmanned probe of the outer solar system and beyond, launched September 5, 1977, and currently operational. ... Voyager 2 is an unmanned interplanetary spacecraft. ...

Instruments located two previously undiscovered small moons and an additional ring, charted Saturn's magnetosphere and magnetic field and found its planet-size moon, Titan, to be too cold for life. Hurtling underneath the ring plane, Pioneer 11 sent back amazing pictures of Saturn's rings. The rings, which normally seem bright when observed from Earth, appeared dark in the Pioneer pictures, and the dark gaps in the rings seen from Earth appeared as bright rings.

Outer regions of the Solar system

Pioneer 11 explored the outer regions of our Solar system, studying the Solar Wind and cosmic rays entering our portion of the Milky Way. The spacecraft has operated on a backup transmitter since launch. Instrument power sharing began in February 1985 due to declining generator power output. Science operations and daily telemetry ceased on September 30, 1995 when the RTG power level was insufficient to operate any experiments. As of the end of 1995, when its mission ended, the spacecraft was located at 44.7 AU from the Sun at a nearly asymptotic latitude of 17.4 degrees above the solar equatorial plane and was heading outward at 2.5 AU/year (12 km/s). There have been no communications with Pioneer 11 since, because Earth's motion has carried it out of alignment with the spacecraft antenna. As this cannot be maneuvered to point back at the Earth, it's unknown whether the spacecraft is still transmitting a signal. The spacecraft is headed toward the constellation of Aquila (The Eagle), Northwest of the constellation of Sagittarius. Pioneer 11 will pass near one of the stars in the constellation in about 4 million years. Telemetry is a technology that allows the remote measurement and reporting of information of interest to the system designer or operator. ... September 30 is the 273rd day of the year (274th in leap years) in the Gregorian calendar, with 92 days remaining. ... 1995 (MCMXCV) was a common year starting on Sunday of the Gregorian calendar. ... The astronomical unit (AU or au or a. ...

Timeline

April 19 is the 109th day of the year in the Gregorian calendar (110th in leap years). ... 1974 (MCMLXXIV) was a common year starting on Tuesday. ... December 2 is the 336th day (337th in leap years) of the year in the Gregorian calendar. ... 1974 (MCMLXXIV) was a common year starting on Tuesday. ... September 1 is the 244th day of the year (245th in leap years). ... This page refers to the year 1979. ... February is the second month of the year in the Gregorian Calendar. ... This article is about the year. ... September 30 is the 273rd day of the year (274th in leap years) in the Gregorian calendar, with 92 days remaining. ... 1995 (MCMXCV) was a common year starting on Sunday of the Gregorian calendar. ... Look up November in Wiktionary, the free dictionary. ... 1995 (MCMXCV) was a common year starting on Sunday of the Gregorian calendar. ...

The Pioneer Plaque

Like its sister ship, Pioneer 10, Pioneer 11 carried a plaque with a message from humankind. If the space probe is ever found by extraterrestrial intelligences, this message is meant to provide information about the origin of the spacecraft. It includes a drawing depicting a man, a woman, the transition of a hydrogen atom, and the location of the Sun and Earth in the galaxy. On board the unmanned spacecraft Pioneer 10 and Pioneer 11 is a plaque with a pictorial message from mankind. ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin for wise man or knowing man) under the family Hominidae (the great apes). ... This article or section seems not to be written in the formal tone expected of an encyclopedia entry. ... NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light years in diameter and approximately 60 million light years distant. ...

Pioneer anomaly

Analysis of the radio tracking data from the Pioneer 10 and 11 spacecraft at distances between 20–70 AU from the Sun has consistently indicated the presence of an anomalous, small Doppler frequency drift. The drift can be interpreted as being due to a constant acceleration of (8.74 ± 1.33) × 10⁻¹⁰ m/s² directed towards the Sun. Although it is suspected that there is a systematic origin to the effect, none has been found. As a result, the nature of this anomaly has become of growing interest. The Pioneer anomaly or Pioneer effect refers to the observed deviation from expectations of the trajectories of various unmanned spacecraft visiting the outer solar system, notably Pioneer 10 and 11. ... This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... An anomaly is a deviation from the common rule. ...

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